The present invention relates to a package structure of an inverter apparatus and a method of manufacturing the same, and more particularly to a package structure of an inverter apparatus and a method of manufacturing the same that can be suitably applied to increase the strength of the package structure.
Conventionally, metallic packages formed by combinations of aluminum die-cast members and metal sheets so as to support heavy components such as an electrolytic capacitor and a cooling fin have been used for inverter apparatuses.
FIG. 6 is an exploded perspective view showing a package structure of a conventional inverter apparatus, and FIG. 7 is an exploded perspective view showing the interior of the package structure of the conventional inverter apparatus.
As shown in FIG. 6, in the package structure of the inverter apparatus, aluminum die-cast members 101a and 101b having substantially the same length as the width of the inverter apparatus are provided in an upper part and a lower part, respectively. The upper and lower aluminum die-cast members 101a and 101b are connected to each other by side metal sheets 103a and 103b which constitute casings of both sides of the inverter apparatus, a frame metal sheet 106, and a rear plate 112.
A cooling fin 113 and an electrolytic capacitor 115 are mounted on the frame metal sheet 106, and a ceiling cover 102 is mounted on a ceiling surface of the inverter apparatus. It should be noted that the side metal sheets 103a and 103b, frame metal sheet 106, and rear plate 112 can be connected to the aluminum die-cast members 101a and 101b by screws.
As shown in FIG. 7, metal sheets on which built-in components such as a main circuit terminal block 110 and a printed-circuit board 111 are mounted on the side sheet-metals 103a and 103b and supporting sheet-metals mounted thereon.
For example, a method in which a front cover is placed on four supports with high strength for ventilating covers mounted on a ceiling surface and a bottom surface and is then secured to the supports by screws so as to reduce man-hours has been disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2005-243741.
In the package structure of the conventional inverter apparatus, however, the package strength of the inverter apparatus is secured by the upper and lower aluminum die-cast members 101a and 101b, side metal sheets 103a and 103b, and frame metal sheet 106. Thus, to install heavy components such as a cooling fin 113 and an electrolytic capacitor 115 in the early stage of assembly, the side metal sheets 103a and 103b are mounted on the aluminum die-cast members 101a and 101b in the early stage of assembly so as to secure s strength of the package, and therefore, there are some limitations as to tools for assembly.
Also, in the package structure of the conventional inverter apparatus, the aluminum die-cast members 101a and 101b having substantially the same length as the width of the inverter apparatus are used. Therefore, the shapes of the aluminum die-cast members 101a and 101b are limited by the width of the inverter apparatus. Thus, it is necessary to fabricate aluminum die-cast members 101a and 101b for each width of inverter apparatus, which significantly increases costs for manufacturing the aluminum die-cast members.
Further, since built-in components such as a main circuit terminal block 110 and a printed-circuit board 111 are mounted on the side metal sheets 103a and 103b which are substantially flat-shaped, there may be cases where built-in components, which are sometimes very fragile, are broken by resonance of the side metal sheets 103a and 103b. Accordingly, the package structure of the conventional inverter apparatus has to be reinforced by installing beams in transverse direction or the like.
An objective of the present invention is to provide a package structure of an inverter apparatus that can support heavy components without using side metal sheets, so that there is no limitation on the width of the inverter apparatus by the size of aluminum die-cast members.
Further objectives and advantages of the invention will be apparent from the following description of the invention.